Low-Power Consumption Hybrid Precoding for Millimeter Wave MIMO Systems

Due to the large amount of phase shifters in millimeter wave (mmWave) MIMO system, it still suffers considerable power consumption. In this paper, a low power consumption phase-modulated array (PMA) based hybrid precoding structure is proposed, in which the analog part consists of delay lines and switches, instead of phase shifters. Different from the traditional hybrid precoding structure, the proposed one can control not only the phase but also the amplitude by selecting corresponding delay lines and adjusting their switch-on time. Furthermore, to achieve the near optimal spectral efficiency, an enhanced orthogonal constraint algorithm is developed for the full-connected PMA based hybrid precoding structure, and an alternating optimization algorithm is proposed for the subconnected PMA based hybrid precoding structure. Simulation results show that, the proposed scheme performs much better in terms of spectral efficiency and energy efficiency.